A typical example of the flexible display includes a film which is made of a synthetic resin such as polyimide (hereinafter, referred to as “plastic film”), and elements supported by the plastic film, such as TFTs (Thin Film Transistors) and OLEDs (Organic Light Emitting Diodes). The plastic film functions as a flexible substrate. The flexible display is encapsulated with a gas barrier film (encapsulation film) because an organic semiconductor layer which is a constituent of the OLED is likely to deteriorate due to water vapor.
Production of the flexible display can be carried out using a glass base on which a plastic film is formed over the upper surface. The glass base functions as a support (carrier) for keeping the shape of the plastic film flat during the production process. Elements such as TFTs and OLEDs, a gas barrier film, and the other constituents are formed on the plastic film, whereby the structure of a flexible OLED device is realized while it is supported by the glass base. Thereafter, the flexible OLED device is delaminated from the glass base and gains flexibility. The entirety of a portion in which elements such as TFTs and OLEDs are arrayed can be referred to as “functional layer region”.
Patent Document No. 1 discloses the method of irradiating the interface between a flexible substrate and a glass base with ultraviolet laser light (lift-off light) in order to delaminate from the glass base the flexible substrate with OLED devices provided thereon. According to the method disclosed in Patent Document No. 1, an amorphous silicon layer is provided between the flexible substrate and the glass base. The irradiation with the ultraviolet laser light causes generation of hydrogen from the amorphous silicon layer and causes the flexible substrate to be delaminated from the glass base.